Energy Systems Engineering / Enerji Sistemleri Mühendisliği
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Review Citation - Scopus: 5A Comparative Evaluation of Dark Fermentative Bioreactor Configurations for Enhanced Hydrogen Production(Springer, 2025) Gören, Ayşegül Yağmur; Dincer, I.; Khalvati, A.Energy from renewable resources has been growing in popularity, which ultimately helps reduce emissions of greenhouse gases (GHGs) and contaminants. Since hydrogen (H2) has a higher combustion production of energy than hydrocarbon fuels, it has been identified as a clean, sustainable, and environmentally friendly energy source. There are several benefits to producing biohydrogen (bioH2) from renewable sources, including lower cost and increased sustainability. Among the bioH2 production processes, dark fermentation supports commercialization and scale-up for industrial applications. This paper considers the various bioreactors, such as anaerobic sequencing batch, continuous stirred, up-flow, fixed-bed, and membrane reactors, and their operational approaches for bioH2 production. This review paper also performs the bibliometric analysis method to identify historical and current developments in a particular field of reactor configuration studies. Furthermore, the main variables influencing reactor performance and methods for increasing process efficiency considering economic and environmental aspects are addressed. The results revealed that continuously stirred reactors are widely utilized for bioH2 production as a cost-effective reactor configuration. Moreover, the membrane bioreactors and fixed-bed reactors are yielded higher bioH2 performance than other configurations. Nevertheless, high energy consumption and costs have presented the need for further development of reactors. Consequently, future recommendations to solve the critical problems faced in reactor configurations, the gaps in the literature, and the points that need improvement were comprehensively reported. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.Article Citation - WoS: 9Citation - Scopus: 11Experimental Investigation of Spray Characteristics of Ethyl Esters in a Constant Volume Chamber(Springer, 2024) Ulu, A.; Yildiz, G.; Özkol, Ü.; Rodriguez, A.D.Abstract: Biodiesels are mainly produced via the utilization of methanol in transesterification, which is the widespread biodiesel production process. The majority of this methanol is currently obtained from fossil resources, i.e. coal and natural gas. However, in contrast with methanol, biomass-based ethanol can also be used to produce biodiesels; this could allow the production line to become fully renewable. This study aimed to investigate the spray characteristics of various ethyl ester type biodiesels derived from sunflower and corn oils in comparison to methyl esters based on the same feedstocks and reference petroleum-based diesel. Spray penetration length (SPL) and spray cone angle (SCA) were experimentally evaluated in a constant volume chamber allowing optical access, under chamber pressures of 0, 5, 10 and 15 bar and injection pressures of 600 and 800 bar. Sauter mean diameter (SMD) values were estimated by using an analytical correlation. Consequently, ethyl esters performed longer SPL (2.8–20%) and narrower SCA (5.1–19%) than diesel under ambient pressures of 5 and 10 bar. Although the SMD values of ethyl esters were 48% higher than diesel on average, their macroscopic spray characteristics were very similar to those of diesel under 15 bar chamber pressure. Moreover, ethyl esters were found to be very similar to methyl esters in terms of spray characteristics. The differences in SPL, SCA and SMD values for both types of biodiesels were lower than 4%. When considering the uncertainty (± 0.84%) and repeatability (±5%) ratios, the difference between the spray characteristics of methyl and ethyl esters was not major. Graphical abstract: [Figure not available: see fulltext.] © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Article Citation - WoS: 22Citation - Scopus: 24Design, Evaluation, and Optimization of an Integrated Proton Exchange Membrane and Double Flash Geothermal Based Organic Rankine Cycle Multi-Generation System Fed by a Biomass-Fueled Gasifier(Elsevier, 2024) Taheri, Muhammad Hadi; Seker, Utku; Akkurt, Gulden Gokcen; Mohammadpourfard, MousaThis study introduces an innovative approach by formulating and evaluating a synergistic biomass-geothermal structure, emphasizing optimized inter-component connections. The research stands out for its thorough analysis of parameter impacts on the system and variables, addressing an unexplored aspect in integrated energy systems. The multi-generation systems are the integration of a combined gasification gas turbine cycle, double flash geothermal cycle, and proton exchange membrane cycle for the generating power and hydrogen. The overall system and its subsystems are studied to explore how the performance of thermodynamics and the total cost rate are influenced by operating parameters. The best operational conditions for both subsystems and the overall system have been determined by analyzing the impact of operating parameters on the thermodynamic behavior and environmental impact through parametric studies. The findings indicate while Sabalan's current efficiency is 16.26 %, the system energy efficiency reached 24.89 % when coupled with other renewable source. To enhance the system's efficiency, a genetics algorithm was utilized to simultaneously optimize the total cost of exergy destruction and investment cost. The outcome of the multi-objective optimization revealed that the exergy efficiency of optimal point for the system is 29.8 % and a total investment cost is 6 (M$/year).Article Citation - WoS: 5Citation - Scopus: 5Exergetic Assessment of an Solar Powered Stand-Alone System Using Liquid Organic Hydrogen Carrier for Energy Storage(Elsevier, 2023) Palmero-Marrero, Ana I.; Zairov, Rüstem; Borge-Diez, David; Çağlar, Başar; Açıkkalp, Emin; Altuntaş, ÖnderThe integration of energy storage technologies into renewable energy systems has gained increasing attention for continuous supply of the renewable-based enegy. Among different storage alternatives, the use of a Liquid Organic Hydrogen Carrier (LOHC) has a significant potential as a reversible energy carrier for short and longterm energy storage. In this study, the technical and economic performance of an stand-alone renewable energy systems using a LOHC for energy storage have been evaluated by exergy-based methods in addition to simple energy and economic analysis. The analysis of the LOHC-free system was also included to determine the effect of LOHC on the system performance. The system containing phovoltaic (PV) panels, an electrolyzer, a micro gas turbine and hydrogenation/dehydrogenation LOHC units was designed to meet the power, heating and cooling requirement of a residential building. The system modelling and performance evaluation were made by using TRNSYS and EES softwares. Results show that the LOHC-containing system has higher energy and exergy efficiencies and exergoeconomic performance than the LOHC-free system while the latter is economically more feasible than the former due to its low capital investment cost.Article Citation - WoS: 8Citation - Scopus: 11Design, Thermodynamic and Economic Evaluation, and Optimization of Gasoline Production From Refinery Furnaces Flue Gas(Elsevier, 2023) Nazerifard, Reza; Mohammadpourfard, Mousa; Heris, Saeed ZeinaliIn this paper, the conversion of refinery furnaces’ flue gas into gasoline through the MTG process is investigated. This approach not only reduces greenhouse gas emissions, but also produces a high-value product, providing economic incentives to adopt this technology. The proposed integrated system comprises an organic Rankine cycle, an amine-based carbon capture unit, a methanol synthesis unit, and an MTG unit. In this study, we evaluated the technical and economic aspects of this conversion process, including the thermodynamic and cost analysis, to assess its viability as a sustainable solution for mitigating CO2 emissions from refineries. Also, using response surface methodology combined with the Box-Behnken design, the proposed integrated system was optimized to minimize the gasoline production cost. The thermodynamic assessment concludes that the energy and exergy efficiencies of the overall system are 73.12% and 85.24%, respectively. The proposed system yields an annual gasoline production rate of >184 million liters. The estimated total capital investment for the proposed system is 172.16 M$, which the methanol synthesis unit with a share of 48.65% is the most expensive one. The results give a gasoline production cost of 1.58 $/kg or 4.28 $/gal for the optimized case. Also, hydrogen has the highest contribution in the production cost, so with a 20% decrease in the price of hydrogen, the production cost of gasoline decreases by 18.71%. With this rate of technological improvement, reductions in the price of hydrogen seem inevitable in not-so-distant years, which makes the proposed system of converting refinery furnaces’ flue gas into gasoline became desirable. © 2023 Elsevier LtdArticle Citation - WoS: 12Citation - Scopus: 13Integration of Psychological Parameters Into a Thermal Sensation Prediction Model for Intelligent Control of the Hvac Systems(Elsevier, 2023) Turhan, Cihan; Özbey, Mehmet Furkan; Lotfi, Bahram; Gökçen Akkurt, GüldenConventional thermal comfort models take physiological parameters into account on thermal comfort models. On the other hand, psychological behaviors are also proven as a vital parameter which affects the thermal sensation. In the literature, limited studies which combine both physiological and psychological parameters on the thermal sensation models are exist. To this aim, this study develops a novel Thermal Sensation Prediction Model (TSPM) in order to control the HVAC system by considering both parameters. A data-driven TSPM, which includes Fuzzy Logic (FL) model, is developed and coded using Phyton language by the authors. Two physiological parameters (Mean Radiant Temperature and External Temperature) and one psychological parameter (Emotional Intensity Score (EIS) including Vigour, Depression, Tension with total of 32 subscales) are selected as inputs of the model. Besides the physiological parameters which are decided intentionally considering a manual ventilated building property, the most influencing three sub- psychological parameters on thermal sensation are also selected in the study. While the physiological parameters are measured via environmental data loggers, the psychological parameters are collected simultaneously by the Profile of Mood States questionnaire. A total of 1159 students are participated to the questionnaire at a university study hall between 15th of August 2021 and 15th of September 2022. The results showed that the novel model predicted Thermal Sensation Vote (TSV) with an accuracy of 0.92 of R2. The output of this study may help to develop an integrated Heating Ventilating and Air Conditioning (HVAC) system with Artificial Intelligence – enabled Emulators that also includes psychological parameters. © 2023 Elsevier B.V.Review Citation - WoS: 21Citation - Scopus: 23A Comprehensive Review of Computational Fluid Dynamics Simulation Studies in Phase Change Materials: Applications, Materials, and Geometries(Springer, 2023) Soodmand, A. Mohammadian; Azimi, B.; Nejatbakhsh, S.; Pourpasha, H.; Farshchi, M. Ebrahimi; Aghdasinia, H.; Mohammadpourfard, Mousa; Heris, S. ZeinaliThermal energy storage systems (TESS) have emerged as significant global concerns in the design and optimization of devices and processes aimed at maximizing energy utilization, minimizing energy loss, and reducing dependence on fossil fuel energy for both environmental and economic reasons. Phase change materials (PCMs) are widely recognized as promising candidates due to their high latent heat storage (LHS) capacity. This review thoroughly evaluates the computational fluid dynamics (CFD) studies conducted in various sections, encompassing materials, modeling, simulation, as well as the results, advantages, and disadvantages of these works. The study is organized into three distinct sections. The first section discusses the applications of PCMs in various areas, including lithium-ion batteries, solar applications, building applications, electronics, and heating and cooling systems. The second section provides a comprehensive summary of cylindrical, rectangular, spherical, arbitrary shapes, and packed-bed geometries employed in TESS. The third section investigates the different types of materials used as PCMs. Based on the findings of this study, it can be concluded that industrial applications of hybrid nanocomposites incorporating PCMs in different geometries pose challenges, particularly in three-dimensional (3D) settings, where instability becomes a significant concern. Hence, further research and investigation are necessary to address these challenges adequately. In conclusion, this study serves as a reference review for future research endeavors in the field of simulating various PCMs in different geometries and applications. It provides valuable insights into the current state of knowledge, highlights potential areas for improvement, and offers guidance for advancing simulation techniques related to PCMs.Article Citation - WoS: 1Citation - Scopus: 1Experimental Investigation of Naca 4415 Airfoil Using Vibration Data for Stall Detection(Emerald Group Publishing, 2023) Ayaz Ümütlü, Hatice Cansu; Kıral, Zeki; Karadeniz, Ziya HaktanPurposeThe purpose of this study is to identify the possible relation between the vibration and the stall by using the vibration response of the airfoil. For this purpose, the root mean square values of the acceleration signals are evaluated to demonstrate the compatibility between the stall angles and the vibration levels. Design/methodology/approachAn experimental study is conducted on NACA 4415 airfoil at Reynolds numbers 69e3, 77e3 and 85e3. Experiments are performed from 0 & DEG; to 25 & DEG; of the angles of attack (AoA) for each Reynolds number condition. To observe the change of the vibration values at the stall region clearly, experiments are performed with the AoA ranging from 10 & DEG; to 25 & DEG; in 1 & DEG; increments. Three acceleration sensors are used to obtain the vibration data. FindingsThe results show that the increase in the amplitude of the vibration is directly related to the decrease in lift. These findings indicate that this approach could be beneficial in detecting stall on airfoil-type structures. Originality/valueThis study proposes a new approach for detecting stall over the airfoil using the vibration data.Article Citation - WoS: 103Citation - Scopus: 113Preparation and Characterizations of Tio2/Zno Nanohybrid and Its Application in Photocatalytic Degradation of Tetracycline in Wastewater(Elsevier, 2023) Zeinali Heris, Saeed; Etemadi, Martin; Mousavi, Seyed Borhan; Mohammadpourfard, Mousa; Ramavandi, BahmanThe photodegradation of tetracycline antibiotics (TC) in an aqueous solution, using the TiO2 nanoparticles, ZnO microparticles, and TiO2/ZnO composite under the UV lamp in a continuous reactor, was performed. The effects of different parameters, such as the initial TC concentration, medium pH, ratio of each photocatalyst, and the flow rate were comprehensively studied. SEM, EDX, and XRD characterization techniques were employed to study the morphology and structure features of the prepared composite. The results revealed that a more significant amount of TC is not easily removed from wastewater. Furthermore, by increasing the pH of the medium to 11, the efficiency of TC degradation was increased, while the amount of removal remained stable at higher pH values. As the flow rate increased up to 190 mL/min, the removal efficiency increased; however, at higher flow rates, lower efficiency was obtained. Moreover, using multivariate analysis and response surface methodology (RSM), a model for removing TC and the effect of experimental parameters on removal efficiency was proposed. The optimal conditions using the RSM method were found to be the reduction efficiency of 78.94 % in pH = 11 (flow rate of 132 mL/min, and TiO2 concentration of 323 mg) and reduction efficiency of 75.89% in pH = 9 (flow rate of 143.19 mL/min and TiO2 concentration of 312.73 mg). © 2023 Elsevier B.V.Article Citation - WoS: 3Citation - Scopus: 3Investigation of External Magnetic Field Effect on the Performance of Ferrofluid-Based Single-Phase Natural Circulation Loops(Elsevier, 2023) Bozkır, Selim Can; Çobanoğlu, Nur; Doğanay, Serkan; Karadeniz, Ziya Haktan; Elçioğlu, Elif Begüm; Turgut, AlpaslanThe goal of this study is to investigate the performance of a Single-Phase Natural Circulation mini Loop (SPNCmL) operating under the influence of an external magnetic field (EMF). For this purpose, a numerical SPNCmL model working with Fe3O4 ferrofluids (1-3 vol%.) under the influence of an EMF is developed to reflect the effect of a NdFeB permanent magnet with a remanence of 1.22 T located at the outlet of the cooler-end for the magnetic field generation. System characteristics such as temperature difference at heater-end (& UDelta;Theater) and maximum temperature (Tmax) and performance in terms of effectiveness (& epsilon;) are investigated. In addition, the effect of EMF on boundary layer energy transport along the cooler-end is evaluated in terms of the change in the local Nusselt number. Applying an EMF dramatically affects the system performance in terms of an increase in & UDelta;Theater and & epsilon;, respectively up to 34% and 25% compared to those with water. Tmax values are obtained by up to 9% higher for Fe3O4 ferrofluids compared to water, while applying EMF results in an increment in Tmax by up to 5%. Improved heat transfer performance by employing EMF at the cooler-end outlet of the SPNCmLs emphasizes their potential in cooling applications.
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